What two figures (one in range a-i and the other in range 1-9) is the odd ones that should be switched to restore both patterns, and why?
created by myself
Swap between i) and 3). I now assume that objects can be hidden by other objects, which may or may not be legal. Again, looking at the difference (but this time, ignoring position) we get
... now subtract the left from the right, we get a nice distribution of crosses.
Swap C and 9.
I based this on the center pieces of each block and matching shapes. Shapes on each block stay the same, just different count, location, and some are overlapping.